xref: /linux/tools/bpf/bpftool/main.c (revision 37744feebc086908fd89760650f458ab19071750)
1 // SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 /* Copyright (C) 2017-2018 Netronome Systems, Inc. */
3 
4 #include <ctype.h>
5 #include <errno.h>
6 #include <getopt.h>
7 #include <linux/bpf.h>
8 #include <stdio.h>
9 #include <stdlib.h>
10 #include <string.h>
11 
12 #include <bpf/bpf.h>
13 #include <bpf/libbpf.h>
14 
15 #include "main.h"
16 
17 #define BATCH_LINE_LEN_MAX 65536
18 #define BATCH_ARG_NB_MAX 4096
19 
20 const char *bin_name;
21 static int last_argc;
22 static char **last_argv;
23 static int (*last_do_help)(int argc, char **argv);
24 json_writer_t *json_wtr;
25 bool pretty_output;
26 bool json_output;
27 bool show_pinned;
28 bool block_mount;
29 bool verifier_logs;
30 bool relaxed_maps;
31 struct pinned_obj_table prog_table;
32 struct pinned_obj_table map_table;
33 
34 static void __noreturn clean_and_exit(int i)
35 {
36 	if (json_output)
37 		jsonw_destroy(&json_wtr);
38 
39 	exit(i);
40 }
41 
42 void usage(void)
43 {
44 	last_do_help(last_argc - 1, last_argv + 1);
45 
46 	clean_and_exit(-1);
47 }
48 
49 static int do_help(int argc, char **argv)
50 {
51 	if (json_output) {
52 		jsonw_null(json_wtr);
53 		return 0;
54 	}
55 
56 	fprintf(stderr,
57 		"Usage: %s [OPTIONS] OBJECT { COMMAND | help }\n"
58 		"       %s batch file FILE\n"
59 		"       %s version\n"
60 		"\n"
61 		"       OBJECT := { prog | map | cgroup | perf | net | feature | btf | gen | struct_ops }\n"
62 		"       " HELP_SPEC_OPTIONS "\n"
63 		"",
64 		bin_name, bin_name, bin_name);
65 
66 	return 0;
67 }
68 
69 static int do_version(int argc, char **argv)
70 {
71 	if (json_output) {
72 		jsonw_start_object(json_wtr);
73 		jsonw_name(json_wtr, "version");
74 		jsonw_printf(json_wtr, "\"%s\"", BPFTOOL_VERSION);
75 		jsonw_end_object(json_wtr);
76 	} else {
77 		printf("%s v%s\n", bin_name, BPFTOOL_VERSION);
78 	}
79 	return 0;
80 }
81 
82 int cmd_select(const struct cmd *cmds, int argc, char **argv,
83 	       int (*help)(int argc, char **argv))
84 {
85 	unsigned int i;
86 
87 	last_argc = argc;
88 	last_argv = argv;
89 	last_do_help = help;
90 
91 	if (argc < 1 && cmds[0].func)
92 		return cmds[0].func(argc, argv);
93 
94 	for (i = 0; cmds[i].func; i++)
95 		if (is_prefix(*argv, cmds[i].cmd))
96 			return cmds[i].func(argc - 1, argv + 1);
97 
98 	help(argc - 1, argv + 1);
99 
100 	return -1;
101 }
102 
103 bool is_prefix(const char *pfx, const char *str)
104 {
105 	if (!pfx)
106 		return false;
107 	if (strlen(str) < strlen(pfx))
108 		return false;
109 
110 	return !memcmp(str, pfx, strlen(pfx));
111 }
112 
113 /* Last argument MUST be NULL pointer */
114 int detect_common_prefix(const char *arg, ...)
115 {
116 	unsigned int count = 0;
117 	const char *ref;
118 	char msg[256];
119 	va_list ap;
120 
121 	snprintf(msg, sizeof(msg), "ambiguous prefix: '%s' could be '", arg);
122 	va_start(ap, arg);
123 	while ((ref = va_arg(ap, const char *))) {
124 		if (!is_prefix(arg, ref))
125 			continue;
126 		count++;
127 		if (count > 1)
128 			strncat(msg, "' or '", sizeof(msg) - strlen(msg) - 1);
129 		strncat(msg, ref, sizeof(msg) - strlen(msg) - 1);
130 	}
131 	va_end(ap);
132 	strncat(msg, "'", sizeof(msg) - strlen(msg) - 1);
133 
134 	if (count >= 2) {
135 		p_err("%s", msg);
136 		return -1;
137 	}
138 
139 	return 0;
140 }
141 
142 void fprint_hex(FILE *f, void *arg, unsigned int n, const char *sep)
143 {
144 	unsigned char *data = arg;
145 	unsigned int i;
146 
147 	for (i = 0; i < n; i++) {
148 		const char *pfx = "";
149 
150 		if (!i)
151 			/* nothing */;
152 		else if (!(i % 16))
153 			fprintf(f, "\n");
154 		else if (!(i % 8))
155 			fprintf(f, "  ");
156 		else
157 			pfx = sep;
158 
159 		fprintf(f, "%s%02hhx", i ? pfx : "", data[i]);
160 	}
161 }
162 
163 /* Split command line into argument vector. */
164 static int make_args(char *line, char *n_argv[], int maxargs, int cmd_nb)
165 {
166 	static const char ws[] = " \t\r\n";
167 	char *cp = line;
168 	int n_argc = 0;
169 
170 	while (*cp) {
171 		/* Skip leading whitespace. */
172 		cp += strspn(cp, ws);
173 
174 		if (*cp == '\0')
175 			break;
176 
177 		if (n_argc >= (maxargs - 1)) {
178 			p_err("too many arguments to command %d", cmd_nb);
179 			return -1;
180 		}
181 
182 		/* Word begins with quote. */
183 		if (*cp == '\'' || *cp == '"') {
184 			char quote = *cp++;
185 
186 			n_argv[n_argc++] = cp;
187 			/* Find ending quote. */
188 			cp = strchr(cp, quote);
189 			if (!cp) {
190 				p_err("unterminated quoted string in command %d",
191 				      cmd_nb);
192 				return -1;
193 			}
194 		} else {
195 			n_argv[n_argc++] = cp;
196 
197 			/* Find end of word. */
198 			cp += strcspn(cp, ws);
199 			if (*cp == '\0')
200 				break;
201 		}
202 
203 		/* Separate words. */
204 		*cp++ = 0;
205 	}
206 	n_argv[n_argc] = NULL;
207 
208 	return n_argc;
209 }
210 
211 static int do_batch(int argc, char **argv);
212 
213 static const struct cmd cmds[] = {
214 	{ "help",	do_help },
215 	{ "batch",	do_batch },
216 	{ "prog",	do_prog },
217 	{ "map",	do_map },
218 	{ "cgroup",	do_cgroup },
219 	{ "perf",	do_perf },
220 	{ "net",	do_net },
221 	{ "feature",	do_feature },
222 	{ "btf",	do_btf },
223 	{ "gen",	do_gen },
224 	{ "struct_ops",	do_struct_ops },
225 	{ "version",	do_version },
226 	{ 0 }
227 };
228 
229 static int do_batch(int argc, char **argv)
230 {
231 	char buf[BATCH_LINE_LEN_MAX], contline[BATCH_LINE_LEN_MAX];
232 	char *n_argv[BATCH_ARG_NB_MAX];
233 	unsigned int lines = 0;
234 	int n_argc;
235 	FILE *fp;
236 	char *cp;
237 	int err;
238 	int i;
239 
240 	if (argc < 2) {
241 		p_err("too few parameters for batch");
242 		return -1;
243 	} else if (!is_prefix(*argv, "file")) {
244 		p_err("expected 'file', got: %s", *argv);
245 		return -1;
246 	} else if (argc > 2) {
247 		p_err("too many parameters for batch");
248 		return -1;
249 	}
250 	NEXT_ARG();
251 
252 	if (!strcmp(*argv, "-"))
253 		fp = stdin;
254 	else
255 		fp = fopen(*argv, "r");
256 	if (!fp) {
257 		p_err("Can't open file (%s): %s", *argv, strerror(errno));
258 		return -1;
259 	}
260 
261 	if (json_output)
262 		jsonw_start_array(json_wtr);
263 	while (fgets(buf, sizeof(buf), fp)) {
264 		cp = strchr(buf, '#');
265 		if (cp)
266 			*cp = '\0';
267 
268 		if (strlen(buf) == sizeof(buf) - 1) {
269 			errno = E2BIG;
270 			break;
271 		}
272 
273 		/* Append continuation lines if any (coming after a line ending
274 		 * with '\' in the batch file).
275 		 */
276 		while ((cp = strstr(buf, "\\\n")) != NULL) {
277 			if (!fgets(contline, sizeof(contline), fp) ||
278 			    strlen(contline) == 0) {
279 				p_err("missing continuation line on command %d",
280 				      lines);
281 				err = -1;
282 				goto err_close;
283 			}
284 
285 			cp = strchr(contline, '#');
286 			if (cp)
287 				*cp = '\0';
288 
289 			if (strlen(buf) + strlen(contline) + 1 > sizeof(buf)) {
290 				p_err("command %d is too long", lines);
291 				err = -1;
292 				goto err_close;
293 			}
294 			buf[strlen(buf) - 2] = '\0';
295 			strcat(buf, contline);
296 		}
297 
298 		n_argc = make_args(buf, n_argv, BATCH_ARG_NB_MAX, lines);
299 		if (!n_argc)
300 			continue;
301 		if (n_argc < 0)
302 			goto err_close;
303 
304 		if (json_output) {
305 			jsonw_start_object(json_wtr);
306 			jsonw_name(json_wtr, "command");
307 			jsonw_start_array(json_wtr);
308 			for (i = 0; i < n_argc; i++)
309 				jsonw_string(json_wtr, n_argv[i]);
310 			jsonw_end_array(json_wtr);
311 			jsonw_name(json_wtr, "output");
312 		}
313 
314 		err = cmd_select(cmds, n_argc, n_argv, do_help);
315 
316 		if (json_output)
317 			jsonw_end_object(json_wtr);
318 
319 		if (err)
320 			goto err_close;
321 
322 		lines++;
323 	}
324 
325 	if (errno && errno != ENOENT) {
326 		p_err("reading batch file failed: %s", strerror(errno));
327 		err = -1;
328 	} else {
329 		if (!json_output)
330 			printf("processed %d commands\n", lines);
331 		err = 0;
332 	}
333 err_close:
334 	if (fp != stdin)
335 		fclose(fp);
336 
337 	if (json_output)
338 		jsonw_end_array(json_wtr);
339 
340 	return err;
341 }
342 
343 int main(int argc, char **argv)
344 {
345 	static const struct option options[] = {
346 		{ "json",	no_argument,	NULL,	'j' },
347 		{ "help",	no_argument,	NULL,	'h' },
348 		{ "pretty",	no_argument,	NULL,	'p' },
349 		{ "version",	no_argument,	NULL,	'V' },
350 		{ "bpffs",	no_argument,	NULL,	'f' },
351 		{ "mapcompat",	no_argument,	NULL,	'm' },
352 		{ "nomount",	no_argument,	NULL,	'n' },
353 		{ "debug",	no_argument,	NULL,	'd' },
354 		{ 0 }
355 	};
356 	int opt, ret;
357 
358 	last_do_help = do_help;
359 	pretty_output = false;
360 	json_output = false;
361 	show_pinned = false;
362 	block_mount = false;
363 	bin_name = argv[0];
364 
365 	hash_init(prog_table.table);
366 	hash_init(map_table.table);
367 
368 	opterr = 0;
369 	while ((opt = getopt_long(argc, argv, "Vhpjfmnd",
370 				  options, NULL)) >= 0) {
371 		switch (opt) {
372 		case 'V':
373 			return do_version(argc, argv);
374 		case 'h':
375 			return do_help(argc, argv);
376 		case 'p':
377 			pretty_output = true;
378 			/* fall through */
379 		case 'j':
380 			if (!json_output) {
381 				json_wtr = jsonw_new(stdout);
382 				if (!json_wtr) {
383 					p_err("failed to create JSON writer");
384 					return -1;
385 				}
386 				json_output = true;
387 			}
388 			jsonw_pretty(json_wtr, pretty_output);
389 			break;
390 		case 'f':
391 			show_pinned = true;
392 			break;
393 		case 'm':
394 			relaxed_maps = true;
395 			break;
396 		case 'n':
397 			block_mount = true;
398 			break;
399 		case 'd':
400 			libbpf_set_print(print_all_levels);
401 			verifier_logs = true;
402 			break;
403 		default:
404 			p_err("unrecognized option '%s'", argv[optind - 1]);
405 			if (json_output)
406 				clean_and_exit(-1);
407 			else
408 				usage();
409 		}
410 	}
411 
412 	argc -= optind;
413 	argv += optind;
414 	if (argc < 0)
415 		usage();
416 
417 	ret = cmd_select(cmds, argc, argv, do_help);
418 
419 	if (json_output)
420 		jsonw_destroy(&json_wtr);
421 
422 	if (show_pinned) {
423 		delete_pinned_obj_table(&prog_table);
424 		delete_pinned_obj_table(&map_table);
425 	}
426 
427 	return ret;
428 }
429